Plot
summary

The story follows Martha Kivelsen, an astronaut who is in a moon
rover crash while exploring the surface of Jupiter’s moon, Io. The
rover is destroyed so Kivelsen decides to make a sledge from the
rover's parts and drag her partner’s body back to the lander before
her air supply runs out. She has no time to sleep so she takes
drugs to keep her awake and give her energy, but they cause her to
hallucinate. Along the way she hears a voice in her radio claiming
to be Io.